The present invention relates generally to needle tip guards for hypodermic needles.
The advent of Human Immunodeficiency Virus (HIV), combined with the increasing incidence of other bloodborne pathogens such as Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV), present healthcare workers with an occupational hazard unprecedented in modern medicine. The risk of contracting HIV from a needlestick injury is approximately 1 in 250, but for those who contract HIV infection as a result of a needlestick injury the risk becomes 1 in 1. The risk of contracting the/more contagious HBV as a result of a needlestick injury ranges from 1 in 6 to 1 in 30.
There are also over twenty more known bloodborne pathogens which are transmitted via blood and bodily fluids. The presence of any of these pathogens in patients poses a risk to healthcare workers when invasive procedures are performed. Infectious diseases are now the third leading cause of death, behind heart disease and cancer, signifying a growing need for safer hypodermic equipment. Ten years ago, infectious diseases were classified as the fifth leading cause of death, they are now ranked third. This increase of infectious disease is attributed mainly to the over-use of antibiotics and the growing availability of re-usable, hollow-bore hypodermic equipment.
As the population of infected individuals increases, more people will be treated by healthcare workers, further increasing the odds of disease transmission from patient to healthcare worker. Also, the use of disposable hypodermic equipment is increasing at approximately 7% per annum. Additionally, a meaningful number of clusters of patient to patient transmission in the healthcare setting has been identified throughout the world. Early data suggests improper infection control techniques contribute directly to this increase: including improper use of hypodermic equipment, multiple-dose medicine vials; and failure to change protective gloves and gear for each new patient.
Recent studies also cite the discovery of significant blood contamination on re-usable blood collection vacuum tube holders which are routinely used to collect blood from different patients. Common practice is to ship one vacuum tube holder with 100 blood collection needles. It is likely that new routes of disease transmission will also be found in the future. Healthcare workers are increasingly at risk to disease transmission and nurses perform the majority of invasive hypodermic procedures, such as injecting medicine, collecting blood and inserting indwelling intravenous (I.V.) catheters. Nurses and other healthcare personnel are routinely injured by the exposed, sharp lancet of the needle after use on a patient. The critical time where a percutaneous injury can occur is from the moment the needle is withdrawn from the patient, or I.V. port, to the time the contaminated needle is safety discarded.
There are approximately 5.6 million workers in the United States (U.S.) whose jobs place them at risk for sustaining an accidental needlestick injury. Medical literature cites approximately one million reported needlestick accidents occur in the U.S. each year, with an additional two-thirds believed to be unreported. One million injuries per year translates to a needlestick injury, on average, every thirty-two seconds. Prior to the proliferation of HIV and serum hepatitis, a needlestick injury was considered a routine part of providing patient care. A needlestick injury now carries a life-threatening consequence and healthcare workers must live with this terror on a daily basis.
Hypodermic needles are used in a wide variety of invasive medical procedures with approximately 1.2 billion units being consumed on an annual basis. Basically, the great majority of hypodermic needles are intended for a single-use on an individual patient and are provided sterile in a variety of lengths and gauges. Hypodermic needles are normally discarded after a single use into a specially designed, puncture-proof biohazard container.
Hypodermic needles are used in medicine, science, veterinary medicine, the biotechnology and pharmaceutical industries, and also in the chemical industry. Medical and veterinary uses range from injecting medication or diluent into a patient or I.V. port, collecting blood, bodily fluids or specimens from patients and, preparing medication. The biotechnology and pharmaceutical applications mainly involve research where substances, liquids, gases or compounds are injected, mixed or withdrawn through a membrane or barrier into a specimen or controlled field. Chemical industry applications involve injecting or removing substances, liquids, gases or compounds to or from a specimen or controlled field. In each and every instance, whether medical or industrial, exposed needles pose a danger of injuring the user.
In medicine, in addition to the danger of contacting contaminated blood or bodily fluids, highly reactive or toxic substances are used for chemotherapy or therapeutic purposes. In the biotechnology, pharmaceutical and chemical industries, toxic, highly reactive, corrosive materials or substances are combined or withdrawn from a variety of experiments or projects.
Despite all the obvious dangers associated with the use of exposed hypodermics, and the availability of manually activated safety hypodermic devices, unguarded, exposed hypodermic needles still dominate the marketplace. This is due to the common practice in the industry where exposed hypodermic needles are sold at discounted prices and usually come packaged with other medical equipment and supplies. Medical institutions continue to purchase exposed hypodermics in this fashion simply for economic reasons.
The basic problem with many of the present day safety hypodermic devices is that they are meant to be manually activated, or in the language of the medical device industry, they are considered xe2x80x9cactivexe2x80x9d devices. They may have safety shields, retractable needles, moveable sheaths or the like; but they generally require the user to complete another procedure to facilitate engagement of the safety mechanism. Although there are a number of retractable needle into syringe devices available, the manufacturing costs associated with these devices are prohibitively high.
What is needed is a low-cost safety hypodermic apparatus with a universal application.
It is therefore an object of this invention to provide a needle point guard that effectively shields the sharpened distal tip of the needle after use.
It is another object of this invention to provide a safety hypodermic apparatus which is automatic and/or semi-automatic covering, fail-safe and single-use in nature.
It is another object of this invention to provide a safety hypodermic apparatus which looks similar to a standard, exposed, disposable hypodermic needled device (i.e., the needle and needle tip are exposed prior to performing the hypodermic procedure).
It is another object of this invention to provide a safety hypodermic apparatus which conforms to existing procedures for aspirating medication into a syringe, administering injections, and allowing unrestricted access for vascular access or catheter insertion.
It is yet another object of this invention to provide a safety hypodermic apparatus which provides an exposed sharpened tip for bevel-up needle viewing.
It is still another object of this invention to provide a safety hypodermic apparatus which automatically and /or manually entraps or captures the sharpened tip of the needle after use.
It is a further object of this invention to provide a safety hypodermic apparatus which allows medication or diluent to be aspirated into a syringe without prematurely activating the automatic and/or manually covering safety mechanism.
It is a still further object of the invention to provide a safety hypodermic apparatus which can be used with a double lancet needle for piercing a cartridge in a pre-filled syringe, or a stopper in a blood collection vacuum tube.
It is an additional object of this invention to provide a safety hypodermic apparatus which lends itself to automated manufacturing.
It is another object of this invention to minimize any mechanical resistance or component fatigue inherent to the stored energy components of the invention when the hypodermic needle is stored.
It is yet another object of the invention to leave the delicate, sharpened needle tip untouched during assembly procedures, ensuring the sharpest needle tip possible to minimize any patient discomfort during use of the hypodermic device.
It is a further object of the invention to reduce the number of components to the lowest possible number needed to accomplish the intended task of providing acceptable, low cost, fail-safe, single-use hypodermic devices for the healthcare industry.
It is yet another object of the invention to prevent catheter separation from the catheter carrying device until the needle tip is safely contained in a protective cover.
In one embodiment the needle guard assembly of the present invention includes a needle guard that is slidably mounted on a hypodermic needle having a needle tip located at the distal end of the needle. The needle guard contains a movable needle trap that is biased against or toward the hypodermic needle. The needle trap advances over the tip of the needle, entrapping the needle tip as the needle guard is urged forward near the sharpened distal end of the hypodermic needle. A tether, or other limiting means, limits the forward movement of the needle guard along the needle. In one embodiment, the needle guard is manually urged forward along the shaft of the needle by the user. In yet another embodiment, a spring, or other biasing means, is used to move the needle guard along the shaft of the needle.
In another embodiment, a hypodermic needle is attached to a housing or hub. A coil spring is positioned between the hub, or housing, and the needle guard assembly. The spring provides the biasing force for advancing the needle guard assembly forward along the shaft of the needle. Prior to use, the needle guard assembly is releasably retained near the proximal end of the needle by a latching arm that is attached to the hub or housing. In one embodiment, the latching arm is automatically disengaged from the needle guard when a longitudinal compressive force is exerted on the retained needle guard. In yet another embodiment, the latching arm may be disengaged manually by the user.
In another embodiment, a side-loadable needle guard assembly is provided that permits the needle tip protective device to be assembled without disturbing the delicate sharpened needle tip. In one embodiment the side-loadable needle guard assembly includes a slotted configuration. In yet another embodiment, the side-loadable needle guard assembly includes a xe2x80x9cclam-shellxe2x80x9d configuration.
In yet another embodiment, the needle guard assembly includes a coupling mechanism that prevents a mechanical separation from the catheter until the needle tip is safely contained within the needle trap. In one embodiment, the coupling mechanism includes an arm having a proximal end and a distal end. The proximal end of the arm is attached to the movable needle trap. The distal end of the arm includes a projection that is releasably retained within a recess of a catheter hub. Hence, as the needle trap moves inward to entrap the needle tip, the arm also moves inward. The inward movement of the arm causes the arm""s distal projection to be released from the catheter hub recess, thereby permitting a separation between the needle guard assembly and the catheter hub.